Device for Foam-Coating and/or Spraying a Substantially Flat Workpiece

ABSTRACT

A device for in situ foaming and/or injection molding an essentially plate-shaped workpiece ( 14 ), especially a transparent cover element of a vehicle roof, has a tool unit ( 10 ) with an upper tool ( 18 ) and a lower tool ( 20 ) which, together, form a mold cavity ( 22 ) for forming a frame in the area of the edge of the workpiece ( 14 ). The tool unit ( 10 ) encloses at least one elastically deformable shaped gasket ( 30 ) which, with the tool unit ( 10 ) closed, adjoins the edge surface of the workpiece ( 14 ) in an area adjoining a recessed region of the frame, so that the workpiece ( 14 ) is free of foamed or injection molded material adjoining the recessed region after the process of in situ foaming or injecting has been completed.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The invention relates to a device for at least one of foaming andinjection molding of an essentially plate-shaped workpiece in place,especially a transparent cover element of a vehicle roof, having a toolunit with an upper tool and a lower tool which, together, form a moldcavity for forming a frame in the area of the edge of the workpiece.

2. Description of Related Art

In the field of motor vehicles, plate-shaped, flat or even archedworkpieces are used in diverse ways. The workpiece is designed, forexample, as a glass plate which is a component of a transparent slidingroof or lifting and sliding roof and forms the cover element of one. Theglass plate in this application generally has a plastic frame which isformed from a thermoplastic or also from polyurethane foam and can beused for attachment of insert parts and/or to form a peripheral gasket.The insert parts can constitute a connecting element for linking theglass plate to a drive mechanism. The plastic frame is conventionallyfoamed or injection molded onto the glass plate in a molding tool.

A device of the initially named type which is designed as a molding toolis known from German Patent Application DE 101 07 743 A1 andcorresponding to U.S. Pat. No. 6,764,290 and is used to produce aplastic frame of a transparent cover element of a sliding roof, alifting and sliding roof or a spoiler roof of a motor vehicle. Thisdevice comprises a tool unit which is provided with a lower tool and anupper tool for forming a mold cavity and is used to accommodate a glassplate so that a plastic frame can be foamed onto it. The mold cavity issealed, on the one hand, by steel/steel contact formed by the lower tooland the upper tool and on the other by glass/steel contact formed by thetool unit and the glass plate.

Furthermore, glass plates which are used for cover elements aregenerally provided with a so-called C-cut on their edges. For aestheticreasons, it has been desirable for the edge surface made as a C-cut tobe kept free of the in situ foaming or injection, at least in regions.Sealing which is necessary for this purpose, especially partial or alsoperipheral sealing of the cut edge surface in the regions of its radii,when using existing foaming tools is, however, not possible to theextent that a polyurethane foam can be produced in suitable visualquality since sealing of the mold cavity via glass/steel contact is notsuited for this purpose in the regions of the radii.

SUMMARY OF THE INVENTION

The object of the invention is to devise a device for foaming and/orinjection molding of an essentially plate-shaped workpiece in situ forforming a plastic frame with partial recesses, the recesses havingclearly defined edges.

This object is achieved by the device of the invention in which the toolunit has at least one elastically deformable shaped gasket which adjoinsthe edge surface of the workpiece at least in the frame-forming cavityregion with the tool unit closed so that, after the in situ foaming orinjection molding of the frame, the workpiece is free of foamed orinjected material at least in the region adjoining the frame.

The heart of the invention therefore involves forming a region free ofthe foaming or injection molding on the edge surface of the workpieceusing a tool unit with a molded gasket which positively adjoins thepertinent edge surface of the workpiece, and in this connection, due toits deformability, has a clearly defined contact surface so that theframe of the workpiece to be produced can be provided with a visuallydefined recess. The mold cavity in the area in which the recessed regionis to be formed is sealed by the contact between the elasticallydeformable shaped gasket and the plate-shaped workpiece. The device inaccordance with the invention contributes significantly to a positivevisual appearance of the finished workpiece.

The device in accordance with the invention can be used, fundamentally,for any plate-shaped workpieces which are inserted into a tool unit forin situ foaming and/or injection molding with a frame. In particular, bymeans of the device in accordance with the invention, flat or curvedglass plates which are used in a motor vehicle, for example, as a coverelement of a sliding glass roof can be processed. In this case, theglass plate is provided in the tool unit with a plastic frame which isformed, for example, of a polyurethane foam, and is used to accommodatea peripheral gasket and/or to connect the insertion parts to the glassplate so that the glass plate can be joined to the vehiclesuperstructure and a sliding roof drive.

In this connection, the term “glass plate” is defined as the indicatedplate-shaped workpiece formed of an at least partially transparentmaterial, such as glass or a transparent plastic.

Especially advantageous contact behavior of the shaped gasket with thepertinent edge surface of the workpiece can be achieved when the shapedgasket has a front side which at least partially adjoins the edgesurface of the workpiece, with an essentially V-shaped cross section. Ifthe edge surface of the workpiece then has a curved cross section, whenthe workpiece has been inserted into the tool unit, the shaped gasket isadvantageously first placed tangentially on the pertinent edge surfacein order to then produce positive locking with the workpiece in therecessed region by the pressure which builds up when the tool unit isclosed. In one special version, the material which is used for theplastic frame and which is placed in the mold cavity can then penetrateinto the wedge-shaped gap between the workpiece and the shaped gasketand can set there.

In order to achieve simple interchangeability of the shaped gasket in amanner easy to install, the shaped gasket is inserted preferably into aslotted recess of the tool unit.

The slotted recess for the shaped gasket is formed by a tool insert in aspecial embodiment of the device in accordance with the invention. Thisversion can be easily manufactured.

In particular, when foaming glass plates in place with a polyurethaneframe, tolerances generally occur in the dimensions of the glass plate.To be able to equalize these tolerances and to always have the same moldimages produced by the shaped gasket, the shaped gasket preferably lieson a strip-like thrust piece on which the positioning mechanism acts.The shaped gasket can thus be positioned in position (x, y and/or z)depending on the dimensions of the workpiece.

In one special embodiment of the device in accordance with theinvention, the positioning means comprises at least one adjusting screw.This adjusting screw can generally be actuated manually and preferablywithout a tool, but can also be provided with a motorized drive.

Favorable temperature and deformation behavior of the shaped gasket canbe achieved when it is made of silicone. Alternatively, the shapedgasket can also be produced from other elastically deformable plastics.

Transparent cover elements of sliding roofs or the like produced fromglass or plastic are generally made with profiled edge surfaces, theprofiling being made especially as a so-called C-cut profile. This meansthat the transparent cover element is made without sharp edges evenbefore its foaming or injection in place with the frame.

Cover elements which are used in the roof region of motor vehiclesgenerally have an essentially square and especially rectangular plan,then in the tool unit in the region of one or more side edge surfaces ofthe plate-shaped workpiece, there can be a respective shaped gasket.Fundamentally, depending on the requirement, the location of the shapedgaskets with respect to the workpiece can be freely selected.

Other advantages and advantageous configurations of the subject matterin accordance with the invention can be taken from the followingdescription when viewed in conjunction the drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 shows a top view of a tool unit of the device in accordance withthe invention;

FIG. 2 shows a section along the line II-II in FIG. 1;

FIG. 3 shows an enlargement of the encircled region III in FIG. 2;

FIG. 4 shows a top view of the lower tool of the tool unit as shown inFIG. 1;

FIG. 5 shows an enlargement of the region V in FIG. 4;

FIG. 6 shows a perspective front view of a shaped gasket of the toolunit;

FIG. 7 shows a cross section through the shaped gasket as shown in FIG.6;

FIG. 8 shows the side region of the cover element of a sliding vehicleroof; and

FIG. 9 shows a section through the cover element as shown in FIG. 8along the line IX-IX in FIG. 8.

DETAILED DESCRIPTION OF THE INVENTION

One embodiment of the device in accordance with the invention and acover element of a motor vehicle roof produced with this device areshown schematically simplified in the drawings.

FIGS. 1 to 7 show a tool unit 10 for producing a polyurethane plasticframe 16 of the cover element 12 of a motor vehicle roof shown in FIGS.8 & 9. The cover element 12 comprises a slightly curved glass plate 14which is provided with a plastic frame 16. The plastic frame 16, in theinstallation position of the cover element 12 assumes sealing functionsin conjunction with it being cementing on the roof frame.

The device comprises a tool unit 10 which is connected to a mold carrier(not shown) and has an upper tool 18 and a lower tool 20. The upper tool18 can be connected to the upper carrier unit of the mold carrier. Thelower tool 20 can be connected to the lower carrier unit of the moldcarrier.

The tool unit 10, in the production of the plastic frame 16, holds theglass plate 14 and defines a mold cavity 22 in which a polyurethanematerial is placed to form the plastic frame 16 via the gate region 24so that it foams in place to form the plastic frame 16 in the moldcavity 24.

To form a recessed or notched region 26 in the area of the edge surface28 of the glass plate 14, which surface is made as a C-cut, in thecorresponding regions of the lower tool 20, there are shaped gaskets 30,of which the drawings show only the shaped gasket 30 in the left-handregion of the tool unit 10. The gasket which is located in theright-hand region of the tool unit 10 is positioned mirror-symmetricallyto the gasket which is located in the left-hand region of the tool unit10.

In the closed state of the tool unit 10, and when the glass plate 14 isheld, each of the two shaped gaskets 30 adjoin the respective edgesurface of the glass plate with a large amount of positive locking tothe respective edge surface of the glass plate so that polyurethane isprevented from being foamed onto the glass plate in the area adjoiningrespective recessed region 26 in an exact manner. The respectiverecessed region 26 of the polyurethane frame 16 thus acquires clearlydefined edges.

A beam-like design of the shaped gasket 30 is shown, for example, inFIGS. 6 & 7. As these figures show, the shaped gasket 30 has anessentially rectangular base surface 32 and a front surface 34 which hasan essentially V-shaped cross section. An especially good sealing resultin the region of the edge surface 28 can be achieved by this shaping ofthe front surface 34.

In the region of the respective shaped gasket 30, the lower tool 20 ofthe tool unit 10 also has a two-part insert 38 which is fitted into therecess 36 and which forms a slotted recess 40 which is aligned parallelto the side edges of the glass plate 14 and into which the respectiveshaped gasket 30 is fitted.

The shaped gasket 30 rests on a strip-like thrust piece 42 on which apositioning means formed from two adjusting screws 44, 46 acts, so thatthe contact pressure of the shaped gasket 30 against the glass plate 14can be adjusted. The shaped gasket 30, which constitutes an elasticallydeformable component, is produced from silicone in this case.

The contact of the shaped gasket 30 with the edge surface 28 of theglass plate 14 is shown by the broken line in FIG. 9. In this case, theshaped gasket 30 is brought into contact with the edge surface 26obliquely downward.

1-10. (canceled)
 11. Device for at least one of foaming and injectionmolding of a frame onto an essentially plate-shaped workpiece in situ,comprising a tool unit with an upper tool and a lower tool which,together, form a mold cavity for forming the frame in an area of an edgesurface of the workpiece, wherein at least one recess is formed by themold tools adjoining the mold cavity, and wherein the tool unit has atleast one elastically deformable shaped gasket which is received in theat least one recess and adjoins the edge surface of the workpiece atleast in an area at a side of the mold cavity with the tool unit in aclosed position, so that the frame has a defined edge adjoining theworkpiece and surfaces of the workpiece adjoining the frame are free ofmaterial used to form the frame after formation of the frame by said atleast one of in situ foaming or injection molding.
 12. Device as claimedin claim 11, wherein the workpiece is a transparent cover element of avehicle roof.
 13. Device as claimed in claim 11, wherein the shapedgasket has a front side with an essentially V-shaped cross section whichat least partially adjoins the edge surface of the workpiece.
 14. Deviceas claimed in claim 11, wherein the at least one recess for the shapedgasket is formed by a tool insert.
 15. Device as claimed in claim 11,wherein the shaped gasket rests on a strip-like thrust piece and whereina positioning means acts on the thrust piece for adjusting a contactpressure of the shaped gasket on the workpiece.
 16. Device as claimed inclaim 15, wherein the positioning means comprises at least one adjustingscrew.
 17. Device as claimed claim 11, wherein the shaped gasket is madeof silicone.
 18. Device as claimed claim 11, wherein the edge surface ofthe workpiece adjoined by the shaped gasket is curved.
 19. Device asclaimed in claim 18, wherein the edge surface of workpiece is a C-shapedcurved profile.
 20. Device as claimed claim 11, wherein the workpiece isessentially rectangular and said at least one shaped gasket comprises agasket each of plural side edge surfaces of the workpiece.
 21. Device asclaimed in claim 12, wherein the shaped gasket has a front side with anessentially V-shaped cross section which at least partially adjoins theedge surface of the transparent cover element.
 22. Device as claimed inclaim 12, wherein the at least one recess for the shaped gasket isformed by a tool insert.
 23. Device as claimed in claim 12, wherein theshaped gasket rests on a strip-like thrust piece and wherein apositioning means acts on the thrust piece for adjusting a contactpressure of the shaped gasket on the transparent cover element. 24.Device as claimed in claim 23, wherein the positioning means comprisesat least one adjusting screw.
 25. Device as claimed claim 12, whereinthe edge surface of the transparent cover element adjoined by the shapedgasket is curved.
 26. Device as claimed in claim 25, wherein the edgesurface of the transparent cover element is a C-shaped curved profile.27. Device as claimed claim 12, wherein the transparent cover element isessentially rectangular and said at least one shaped gasket comprises agasket each of plural side edge surfaces of the workpiece.
 28. Processof in situ forming a frame on a workpiece, comprising the steps of:providing a tool unit with an upper tool and a lower tool which,together, form a mold cavity for forming the frame in an area of an edgesurface of the workpiece, providing at least one elastically deformableshaped gasket in at least one recess of the tool unit so that the shapedgasket adjoins the edge surface of the workpiece at least in an area ata side of the mold cavity with the tool unit in a closed position, atleast one of in situ foaming or injection molding a material in saidcavity to form the frame with the at least one shaped gasket producing adefined edge on the frame adjoining the workpiece with surfaces of theworkpiece adjoining the frame being free of material used to form theframe.
 29. Process according to claim 28, wherein the workpiece is atransparent cover element of a vehicle roof.